松针瘿蚊越冬幼虫体内酶活性的时序变化

昆虫的越冬耐寒过程与糖酵解、磷酸己糖途径和抗冻保护性物质合成等一些中间代谢有关的酶有关。该文对松针瘿蚊Thecodiplosis japonensis老熟幼虫1998/1999越冬期间体内上述代谢酶活性的变化进行了研究。越冬期间体内糖原磷酸化酶活性明显地增加，糖酵解有关的酶（己糖激酶、乳酸脱氢酶和醛缩酶）活性较低，以保证更多的碳源（糖原）转化成海藻糖。越冬期间，体内葡萄糖-6-磷酸脱氢酶活性增高所产生的还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)，可为细胞在亚低温状态下发挥正常功能以及体内抗冻保护性物质的合成提供还原动力，同时通过调节体内海藻糖酶活性来维持越冬期间较高含量的海藻糖和移除春季体内累积的过多的海藻糖。

Profile of enzymic activity in overwintering mature larvae of the pine needle gall midge,Thecodiplosis japonensis

Insect cold hardening processing is related with the activity of some enzymes of intermediary metabolism, including enzymes of glycolysis, hexose monophosphate shunt and cryoprotectant synthesis. In this study, overwintering larvae of pine needle gall midge, Thecodiplosis japonensis, were sampled at various dates over 1998～1999 winter and the profile of enzymic activity of intermediary metabolism was studied. The increased glycogen phosphorylase during overwintering ensured the required flow of carbon into the synthesis of trehalose. Enzymes of glycolysis (hexokinase, lactate dehydrogenase, aldolase) showed low activities during overwintering when more carbon flowing into trehalose synthesis. The glucose-6-phosphate dehydrogenase increased during overwintering, indicating that reduced condition of cell might keep the cell in proper function even in cold temperature, and also for cryoprotectant synthesis. The changes in trehalase activity showed that low activity was for keeping higher trehalose content and high activity for removing it in the spring.